[General] Firebolt that causes burning oil

[PurrsandMlems]

im trying to make a firebolt spell, which is firebolt + causes burning oil.
how should i get about doing that ?

edit: i have tried to do it through dummy, it would not set the ground on fire.

• Fire Bolt
  • Events
    • Unit - A unit Starts the effect of an ability
  • Conditions
    • (Ability being cast) Equal to Fire Bolt (warlord)
  • Actions
    • Set FireBolt_Target = (Target unit of ability being cast)
    • Unit - Create 1 Attack Dummy (0 Collision) for (Owner of (Triggering unit)) at (Position of FireBolt_Target) facing (Position of FireBolt_Target)
    • Set FireBolt_Dummy = (Last created unit)
    • Unit - Add a 10.00 second Generic expiration timer to FireBolt_Dummy
    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
      • If - Conditions
        • (FireBolt_Target is alive) Equal to True
      • Then - Actions
        • Unit - Add Burning Oil (dummy) to FireBolt_Dummy
        • Custom script: call RemoveLocation(udg_FireBolt_Point)
        • Set FireBolt_Point = (Target point of ability being cast)
        • Unit - Order FireBolt_Dummy to Attack Ground FireBolt_Point
        • Custom script: call RemoveLocation(udg_FireBolt_Point)
      • Else - Actions

could it be that the trigger, or perhaps the dummy was configured incorrectly ? here is the dummy unit definition:

 

[Nichilus]

The dummy is definitely set up incorrectly. Its 'Combat - Attack' fields should be set up same way like a demolisher.
You can even see this now - temporarily remove the locust ability from the dummy, place it in map, select it in game and you will see that it does not have 'Attack Ground' ability.